Season: June - March.
To grow: Cavolo nero is a constant in my garden. It's so easy to grow and is basically self sufficient, I love how reliable it is. Just watch it and make sure to harvest before it goes to flower, as that's when it'll loose its quality and deliciousness, although the flowers make a nice garnish for your dishes.
To eat: It's so full of nutrients that I try to add cavolo nero into as many dishes as I can, also because I constantly have so much of it. Treat it like a more hardy version of spinach with a lot more flavour and texture. There's a delicious recipe for cavolo nero pesto in the Towpath cookbook that I use all the time.